One
of the things that sets our carbon frames apart is our
blending of various carbon fibers types to achieve both
the ride qualities and the price levels that are
perfectly suited for the bikes and riders we are
designing for.

Take a look at the frame material
specs for any carbon fiber frame these days and it seems
nearly every single one is made of ‚Äúhigh modulus‚Äù,
‚Äúsuper high modulus‚Äù, ‚Äúultra high modulus‚Äù, or
some superlative followed by ‚Äúhigh modulus‚Äù. But just
what is ‚Äúhigh modulus‚Äù and why is it good for us?

Once carbon fiber has been
manufactured, it can be further purified via high
temperature processing. This purification process thins
and smoothes the fibers, which can then be packed
together more tightly into the bundles or yarns that are
woven together to make up the fabric we recognize as
carbon fiber. Packing these purified fibers more tightly
yields a stronger, stiffer bundle, so less bundles can be
used to achieve a certain tensile strength and torsional
stiffness, which yields a lighter construction. That‚Äôs
why ‚Äúhigher‚Äù modulus usually means ‚Äúbetter‚Äù.

But it‚Äôs also really stiff. As in brittle. This can be
combated to some degree by careful selection of resins,
but still, a super-light, thin-walled, high modulus-only
frame is going to be more subject to damage on impact
than a lower modulus, thicker-walled frame. That
super-stiff, high-modulus only frame is also going to
ride super-stiff. For the Pros of Jamis-Sutter Home, this
isn‚Äôt undesirable, but it isn‚Äôt the ride quality for
everyone. Not to mention, that super-stiff,
high-modulus-only frame is also super-expensive.

There‚Äôs a cost to the
sophisticated hi-tech processing that takes a strand of
carbon fiber one-tenth the width of a hair and makes it
thinner and smoother. That cost is not marginal or
incremental, it‚Äôs exponential.

Which is why you will find 6
different lay-ups of 4 different types of carbon fiber in
our frames.

30% super-high modulus M40
carbon fiber, 70% high modulus M30 carbon fiber.
Reducing the M40 percentage to 30% and blending the
M30 with the M40 increases frame weight by about 7%,
but increases shock damping for a more comfortable
ride.

100% mid-modulus T700 carbon
fiber. This blend offers greater impact resistance and
more comfort without much of a weight gain (less than
100 grams) over that of the Dyad Elite frames. Xenith
Pro and Race.

DYAD
PLUS(Xenith Comp, Xenith
T1, Xenith T, Xenith Endura Sport)

A blend of mid-modulus T700 and
other carbon composites. Chief goal here is minimizing
cost while maximizing comfort & impact resistance
attributes while still delivering a high level of
torsional stiffness to optimize power transfer.

Key point is that we‚Äôre not
just using ‚Äúhigh modulus‚Äù as marketing verbiage to
define all our frames, while hoping you to have no
idea what modulus is all about. There‚Äôs a place and
a reason for high modulus, and there‚Äôs a place and a
reason for mid-modulus. Describing anything as
‚Äúmid‚Äù may run contrary to the advice of the
Marketing Department, but mid-modulus fiber,
especially when blended with high modulus can still be
light and stiff with some degree of damping and
flexibility for a supple, comfortable ride.

R&D/MANUFACTURING
We‚Äôve designed, built and ridden carbon fiber
monocoques as well as tube-and-lug carbon frames, and
our monocoques were always lighter, more durable, and
simply rode better. Materials overlap in lugged frames
which concentrates stress at the bonded joint. It also
weighs more and contributes to a deader frame feel.
Monocoques are completely unified. Stresses are
distributed over a greater potion of the frame
structure, making for a lighter, stiffer, stronger
frame and one that rides with a snap and liveliness
that‚Äôs its own reward.

A monocoque‚Äôs structural
integrity relies heavily on the lay-up schedule, the
master plan for the location of each and every carbon
ply. We start with Finite Element Analysis (FEA)
software that visualizes where structures bend or
twist and simulates the distribution of stresses and
displacements, this allows us to design, refine and
optimize the materials and lay-up before cutting molds
and burping prototypes, which are then relentlessly
fatigue- and deflection-tested for every frame size.
Failures get kicked back to the lay-up room for some
material massaging and ply re-arrangement until
they‚Äôre good to ride.

Then we suit up for the hard
part of our job. The ride! We ride and record, ride
more and record more. We enlist our pro riders for
evaluation and comment. The beauty of carbon is its
ability to be easily tuned by manual manipulation of
the plies, like tensioning a drum head or guitar
string for absolutely perfect ride quality -- the
just-right balance between stiffness and resilience,
the ability to feel the road.

It‚Äôs important to remember
every carbon frame is handmade. There‚Äôs a skill and
artistry to accurately applying small squares,
rectangles and triangles of carbon fiber according to
the schedule our engineers assign. Just because it‚Äôs
hidden beneath a cosmetic layer of 1K, 6K or 12K weave
doesn‚Äôt mean it isn‚Äôt there, and it‚Äôs no less
skillful or significant than precision welds or
brazing work.

These carbon fiber swatches are
laid up on a silicone mandrel, one at a time, in an
interwoven and overlapping pattern. As each section is
complete the silicone mandrel is removed, each section
is joined to the others, and expandable air bladders
are run through the frame. The frame goes in a steel
mold, the mold goes in an oven, bladders are
pressurized, the oven is heated to melt and disperse
the resin, and then the whole thing is cooled to
harden and cure.

All these steps are necessary to
ensure compaction, which is where it‚Äôs at for carbon
fiber structural integrity. That‚Äôs why we‚Äôve taken
monocoque molding technology to the next level with
our Near Net Molding technology (featured on the 2012
Xenith SL and the Dakota dXC Team frame kit). Near Net
Molding is a revolutionary process utilizing air
bladders and a polystyrene pre-form core that recedes
as the oven heats, assuring an interior that is
‚Äúnear net‚Äù in finish, without the wrinkled fiber
or resin pooling common in most of today‚Äôs carbon
frames. Every gram of resin has been compressed, every
length of fiber has been flattened and aligned.

After hours of hand finishing,
before heading on to the painters and clear coaters,
EVERY frame is weighed to make sure it‚Äôs neither
resin rich nor resin deficient. We also measure the
stiffness of each frame in 6 critical areas as a check
on lay-up production, guaranteeing every frame we
produce will deliver the ride qualities we defined and
demand.

AND MORE
Every Xenith frame also features asymmetric
chainstays for absolutely efficient power transfer
from pedal to wheel, with a drive side chainstay
that‚Äôs 10% larger and an incredible 30% stiffer
to offset drivetrain-induced flex.

Our Xenith fork features full
monocoque hollow construction from dropout to
steerer top, just like our frame, with a 1.5‚Äù
crown and an inner-leg reinforcing rib that
provides exceptional lateral stiffness for
quick-but-predictable handling, with neutral
cornering and hands-off-the-bar stability.
There‚Äôs absolutely no flex or meandering when
sprinting out of the saddle and over the front
wheel, and no dive when pulling on the brakes
heading into a turn.

If this is all starting to
sound like the sort of hype we promised to dispel,
forgive us. We know we‚Äôre on to something and we
just want to share it. If you need some credible,
objective insight and feedback to verify our Xenith
claims, just check out the YouTube video review of
the Xenith SL by cycling legend Frankie Andreu. Or
better yet, head on down to your Jamis dealer for a
test ride. It‚Äôs all hyper-bull until you click in
and put it down. The proof is in the pedaling.

DESCRIPTION

SPECIFICATIONS

GEOMETRY

VIDEO

SUSPENDING REALITYWHY
MP4, MP3 & MP2 MAKE YOU BETTER

All right, we‚Äôll come
right out and say it now: There is no such thing as the
perfect suspension. There simply can‚Äôt be, given the
number of trails, the different styles of riding, the
various skill levels we all possess, not to mention
three possible wheel sizes. No wonder there are so many
viable designs to choose from.

And that‚Äôs the key word there.
Viable. Because despite the variety in suspension
designs, terrain and riding style, the primary goal of
suspension science is pretty simple‚Äîabsorb impact,
negate pedal bob and neutralize brake-jack or rotor-dive
while keeping tires in contact with terrain. Today‚Äôs
shocks are so incredibly smart, they‚Äôre able to do the
lion‚Äôs share of determining where the motion‚Äôs coming
from‚Äîwhether it‚Äôs the legs and pedals, or the
terrain. So between today‚Äôs shock technology, and these
simple suspension goals, there are plenty of available
designs that can accomplish the task.

What separates the winners from the pack isn‚Äôt design,
but execution. And that suits us just fine‚Äîbecause when
it comes to detailed execution, we‚Äôre unbeatable. (Need
proof? Drop by and see the roomful of editor‚Äôs choice
awards we‚Äôve earned for our bikes‚Äîno technical
trickery there, that‚Äôs the power of meticulously
perfect detail and execution.)

PIVOTAL
MATTERS

All great engineering is based
on simplicity. Find the most elemental solution
possible, refine it, reduce the complexity, and
you‚Äôre done. And that‚Äôs how our mp4 suspension has
evolved.

Some of the other guys would
have you believe complexity is a good thing,
outfitting their designs with so many pivots and
bellcranks it‚Äôs a wonder the wheel can move at all.
We‚Äôre not convinced.

A simple design requires fewer
parts, which takes less material and structure, which
means less weight. And it also means fewer bearings,
eliminating weight while reducing unwanted movement
(every bearing has a little slop‚Äîthe more bearings
you have, the more slop you get).

Our mp4, mp3 and mp2 designs
rely basically on a single primary pivot, located just
above and behind the bottom bracket centerline.
Because this single pivot takes most of the load we
don‚Äôt need a plethora of heavy bearings‚Äîjust this
and two other really, really good ones (where the
seatstays connect to the bell crank and where the bell
crank connects to the frame). And because everything
happens at this one primary pivot, we can place it in
such a way that it minimizes braking influences,
reduces pedal kickback and unwanted movement due to
chain tension. Nice!

The seatstay pivot improves
geometry with a consistently near-vertical axle path
throughout the wheel‚Äôs travel, for better suspension
movement over tiny stutters and big hits alike. And
structurally, the bellcrank helps shore up the rear
triangle against lateral movement and improves
torsional rigidity so the rear wheel stays in
plane‚Äîthere‚Äôs no wandering or fishtailing because
the axle‚Äôs so well controlled.

Even though our main pivot is
located in the same BB location on all our mp designs,
we can tune leverage rates with bell crank lengths,
bell crank pivot location and shock position. Our mp2
and mp4 XC designs offer a very slight rising rate in
the first 40% of travel, and then it‚Äôs linear for
the balance of travel. This means you don‚Äôt get a
sudden ramp-up as the suspension
compresses‚Äîthere‚Äôs nearly linear response in the
fat part of the travel curve, for supple action over
stutters and medium hits, with a bit of ramp-up as you
approach the travel limits and a nearly bottomless
suspension feel that‚Äôs ideal for short-travel XC
designs like Dakar XCR 29ers, the XCR Race and the XC
Comp & Sport. On our longer travel XCTs, 650Bs and
AMT, our mp4 Trail design offers a much more
progressive leverage rate. This means the rear shock
can be tuned more linearly (like a coil spring) and
pumped to lower pressures for a smoother, more plush
ride without bottoming.

THE LOW LEVERAGE ADVANTAGEWe‚Äôre huge believers in low
shock leverage ratios ‚Äì all our mp designs have an
average wheel-travel-to-shock-stroke ration of 2.65:1
This is really important, when it comes to suspension
smoothness and durability.

For one thing, you get better
performance from the shock with a lower leverage
ratio. There‚Äôs less force being taken up by the
shock, which reduces stress on the shock internals.
And because you‚Äôre employing more of the shock‚Äôs
throw for the fat part of the travel curve, the
suspension action is much smoother and better
controlled.

A low leverage ratio also means
you don‚Äôt need super high spring rates, which
translates to improved shock sensitivity. External
rebound and compression damping adjustments can be
made in much finer increments, which wouldn‚Äôt make
an appreciable difference on more leveraged designs.
You can make better use of the shock‚Äôs tune-ability
(and today‚Äôs shocks are impressively tuneable).

What‚Äôs more, a lower spring
rate lets you employ a physically lighter coil spring,
or in the case of air springs you can use less
pressure, which improves shock sensitivity and vastly
extends seal life.

EMBRACING
ASYMMETRY

All of our dual suspension
designs (with the exception of the BAM) feature
asymmetric chainstays, with an elevated straight
stay on the non-drive side and a dropped, curving
stay on the drive side. A straight stay uses a
shorter, lighter length of material, and because
it‚Äôs better aligned with suspension forces we can
pare even more weight from it without giving up
rigidity. The drive side is dropped and curved to
clear the front derailleur and chain, and it‚Äôs
shored up a bit since it also has to resist
drivetrain forces. It‚Äôs not the esthetically
balanced look we‚Äôre used to, but the net result
is less weight, more rigidity, lots of tire
clearance and smoother suspension action.

BUILT TO
LAST

Lightness is good, but
strength is paramount. That‚Äôs why we spec 10 mm
shock hardware, oversize pivot bearings and
high-grade fasteners throughout the suspension. You
get greater lateral stiffness and torsional
rigidity, which pays off in better handling and
power delivery that more than makes up any time
lost by carrying a few additional grams.

We carry that weight as low
as possible, which is why we like our low shock
mounting position that lowers the center of gravity
for better handling. And we believe in the
structural bracing power of the triangle. Having
two of them in our suspension designs makes for a
stronger, stiffer frame, qualities we maximize by
keeping those triangles as small and tight as
physical geometry allows for any given frame size
(and also offers the lowest possible standover for
the rider).

We‚Äôre also adding a little
bit of extra weight in the form of the 135x13 mm
Maxle thru-axle, which we use on our, XCR 29, XCT
and Sixfifty B designs because it just brings so
much to the table. There‚Äôs a huge payoff
here‚Äîthreading the rear axle into the dropouts
really ties the whole rear triangle together,
boosting torsional and lateral stiffness‚Äîso you
get more efficient power delivery, and handling
improves markedly since the rear tire‚Äôs forced to
track directly behind the frame. Suspension pivots
last longer, with less binding‚Äîand you experience
better control under braking, with less
fishtailing. It‚Äôs a win!

CONTROL
CENTER

A better rear suspension
means you‚Äôll go faster. And that places more
demands on the fork. More speed translates into
higher cornering forces and braking forces, which
is why we‚Äôve include beefed up the front end on
almost every Jamis mountain bike, with a tapered
1-1/8‚Äù ‚Äì 1.5‚Äù head tube (the BAM offers a
full 1.5‚Äù head tube).

The fork transfers most of
its force into the frame via the lower headset
bearing, and a 1.5‚Äù lower headset is markedly
stronger than the old 1-1/8‚Äù standard. A full
1.5‚Äù head tube would accomplish the same task,
but that oversize top bearing is overkill‚Äîit just
bulks up the front end and adds unnecessary weight,
which is why we‚Äôre glad most fork makers are
embracing the tapered steerer design, so we can
employ this frame spec without limiting our fork
options.

A stiffer front end reduces
brake chatter and gives you better steering
precision. Plus a more rigid control center lets
you muscle your way out of ruts, blast through rock
gardens, and hold your line while bombing g-outs
and railing through berms.

REAL WORLD
PERFORMANCE

We believe in the power
of design and details, and Jamis does both
right. From pivot placement, to just the right
size tubing and materials, to the component
package, to frame alignment, it‚Äôs the
manufacturing and parts specification details,
not just the suspension design, that makes or
breaks the ride. And we believe nobody is better
at this game than we are.

If you‚Äôre shopping for a
bike, you owe it to yourself to check them ALL
out. Keep your eye on the big picture‚Äîdoes it
fit your physique, your trails and riding style?
In the end, what matters most is how the bike
performs, in real woods, on real trails, for
you. Just be sure you try a Jamis‚Äîwe think
you‚Äôll like the way it works in the real
world.

SUSPENDING REALITYWHY MP4, MP3 & MP2
MAKE YOU BETTERAll
right, we‚Äôll come right out and say it now:
There is no such thing as the perfect suspension.
There simply can‚Äôt be, given the number of
trails, the different styles of riding, the
various skill levels we all possess, not to
mention three possible wheel sizes. No wonder
there are so many viable designs to choose from.

And that‚Äôs the key word
there. Viable. Because despite the variety in
suspension designs, terrain and riding style, the
primary goal of suspension science is pretty
simple‚Äîabsorb impact, negate pedal bob and
neutralize brake-jack or rotor-dive while keeping
tires in contact with terrain. Today‚Äôs shocks
are so incredibly smart, they‚Äôre able to do the
lion‚Äôs share of determining where the motion‚Äôs
coming from‚Äîwhether it‚Äôs the legs and pedals,
or the terrain. So between today‚Äôs shock
technology, and these simple suspension goals,
there are plenty of available designs that can
accomplish the task.

What separates the winners from the pack isn‚Äôt
design, but execution. And that suits us just
fine‚Äîbecause when it comes to detailed
execution, we‚Äôre unbeatable. (Need proof? Drop
by and see the roomful of editor‚Äôs choice awards
we‚Äôve earned for our bikes‚Äîno technical
trickery there, that‚Äôs the power of meticulously
perfect detail and execution.)

PIVOTAL
MATTERS All great engineering is based
on simplicity. Find the most elemental solution
possible, refine it, reduce the complexity, and
you‚Äôre done. And that‚Äôs how our mp4
suspension has evolved.

Some of the other guys would have you
believe complexity is a good thing, outfitting
their designs with so many pivots and
bellcranks it‚Äôs a wonder the wheel can move
at all. We‚Äôre not convinced.

A simple design requires fewer parts,
which takes less material and structure, which
means less weight. And it also means fewer
bearings, eliminating weight while reducing
unwanted movement (every bearing has a little
slop‚Äîthe more bearings you have, the more
slop you get).

Our mp4, mp3 and mp2 designs rely
basically on a single primary pivot, located
just above and behind the bottom bracket
centerline. Because this single pivot takes
most of the load we don‚Äôt need a plethora of
heavy bearings‚Äîjust this and two other
really, really good ones (where the seatstays
connect to the bell crank and where the bell
crank connects to the frame). And because
everything happens at this one primary pivot,
we can place it in such a way that it minimizes
braking influences, reduces pedal kickback and
unwanted movement due to chain tension. Nice!

The seatstay pivot improves geometry with
a consistently near-vertical axle path
throughout the wheel‚Äôs travel, for better
suspension movement over tiny stutters and big
hits alike. And structurally, the bellcrank
helps shore up the rear triangle against
lateral movement and improves torsional
rigidity so the rear wheel stays in
plane‚Äîthere‚Äôs no wandering or fishtailing
because the axle‚Äôs so well controlled.

Even though our main pivot is located in
the same BB location on all our mp designs, we
can tune leverage rates with bell crank
lengths, bell crank pivot location and shock
position. Our mp2 and mp4 XC designs offer a
very slight rising rate in the first 40% of
travel, and then it‚Äôs linear for the balance
of travel. This means you don‚Äôt get a sudden
ramp-up as the suspension
compresses‚Äîthere‚Äôs nearly linear response
in the fat part of the travel curve, for supple
action over stutters and medium hits, with a
bit of ramp-up as you approach the travel
limits and a nearly bottomless suspension feel
that‚Äôs ideal for short-travel XC designs like
Dakar XCR 29ers, the XCR Race and the XC Comp
& Sport. On our longer travel XCTs, 650Bs
and AMT, our mp4 Trail design offers a much
more progressive leverage rate. This means the
rear shock can be tuned more linearly (like a
coil spring) and pumped to lower pressures for
a smoother, more plush ride without bottoming.

THE LOW LEVERAGE ADVANTAGEWe‚Äôre huge believers
in low shock leverage ratios ‚Äì all our mp
designs have an average
wheel-travel-to-shock-stroke ration of 2.65:1
This is really important, when it comes to
suspension smoothness and durability.

For one thing, you get
better performance from the shock with a lower
leverage ratio. There‚Äôs less force being
taken up by the shock, which reduces stress on
the shock internals. And because you‚Äôre
employing more of the shock‚Äôs throw for the
fat part of the travel curve, the suspension
action is much smoother and better controlled.

A low leverage ratio also means you
don‚Äôt need super high spring rates, which
translates to improved shock sensitivity.
External rebound and compression damping
adjustments can be made in much finer
increments, which wouldn‚Äôt make an
appreciable difference on more leveraged
designs. You can make better use of the
shock‚Äôs tune-ability (and today‚Äôs shocks
are impressively tuneable).

What‚Äôs more, a lower spring rate lets
you employ a physically lighter coil spring, or
in the case of air springs you can use less
pressure, which improves shock sensitivity and
vastly extends seal life.

EMBRACING
ASYMMETRY All of our dual suspension
designs (with the exception of the BAM)
feature asymmetric chainstays, with an
elevated straight stay on the non-drive side
and a dropped, curving stay on the drive
side. A straight stay uses a shorter,
lighter length of material, and because
it‚Äôs better aligned with suspension forces
we can pare even more weight from it without
giving up rigidity. The drive side is
dropped and curved to clear the front
derailleur and chain, and it‚Äôs shored up a
bit since it also has to resist drivetrain
forces. It‚Äôs not the esthetically balanced
look we‚Äôre used to, but the net result is
less weight, more rigidity, lots of tire
clearance and smoother suspension action.

BUILT TO
LAST Lightness is good, but strength
is paramount. That‚Äôs why we spec 10 mm
shock hardware, oversize pivot bearings and
high-grade fasteners throughout the
suspension. You get greater lateral
stiffness and torsional rigidity, which pays
off in better handling and power delivery
that more than makes up any time lost by
carrying a few additional grams.

We carry that weight as low as
possible, which is why we like our low shock
mounting position that lowers the center of
gravity for better handling. And we believe
in the structural bracing power of the
triangle. Having two of them in our
suspension designs makes for a stronger,
stiffer frame, qualities we maximize by
keeping those triangles as small and tight
as physical geometry allows for any given
frame size (and also offers the lowest
possible standover for the rider).

We‚Äôre also adding a little bit of
extra weight in the form of the 135x13 mm
Maxle thru-axle, which we use on our, XCR
29, XCT and Sixfifty B designs because it
just brings so much to the table. There‚Äôs
a huge payoff here‚Äîthreading the rear axle
into the dropouts really ties the whole rear
triangle together, boosting torsional and
lateral stiffness‚Äîso you get more
efficient power delivery, and handling
improves markedly since the rear tire‚Äôs
forced to track directly behind the frame.
Suspension pivots last longer, with less
binding‚Äîand you experience better control
under braking, with less fishtailing. It‚Äôs
a win!

CONTROL
CENTER A better rear suspension
means you‚Äôll go faster. And that places
more demands on the fork. More speed
translates into higher cornering forces and
braking forces, which is why we‚Äôve include
beefed up the front end on almost every
Jamis mountain bike, with a tapered 1-1/8‚Äù
‚Äì 1.5‚Äù head tube (the BAM offers a full
1.5‚Äù head tube).

The fork transfers most of its force
into the frame via the lower headset
bearing, and a 1.5‚Äù lower headset is
markedly stronger than the old 1-1/8‚Äù
standard. A full 1.5‚Äù head tube would
accomplish the same task, but that oversize
top bearing is overkill‚Äîit just bulks up
the front end and adds unnecessary weight,
which is why we‚Äôre glad most fork makers
are embracing the tapered steerer design, so
we can employ this frame spec without
limiting our fork options.

A stiffer front end reduces brake
chatter and gives you better steering
precision. Plus a more rigid control center
lets you muscle your way out of ruts, blast
through rock gardens, and hold your line
while bombing g-outs and railing through
berms.

REAL
WORLD PERFORMANCE We believe in
the power of design and details, and
Jamis does both right. From pivot
placement, to just the right size tubing
and materials, to the component package,
to frame alignment, it‚Äôs the
manufacturing and parts specification
details, not just the suspension design,
that makes or breaks the ride. And we
believe nobody is better at this game
than we are.

If you‚Äôre shopping for a bike,
you owe it to yourself to check them ALL
out. Keep your eye on the big
picture‚Äîdoes it fit your physique, your
trails and riding style? In the end, what
matters most is how the bike performs, in
real woods, on real trails, for you. Just
be sure you try a Jamis‚Äîwe think
you‚Äôll like the way it works in the
real world.